Files
UnrealEngineUWP/Engine/Source/Runtime/Serialization/Private/StructDeserializer.cpp
Robert Manuszewski 2752c82adc Merging //UE4/Dev-Main @ 4664414 to Dev-Core (//UE4/Dev-Core)
#rb none

[CL 4675693 by Robert Manuszewski in Dev-Core branch]
2019-01-02 00:55:51 -05:00

425 lines
12 KiB
C++

// Copyright 1998-2019 Epic Games, Inc. All Rights Reserved.
#include "StructDeserializer.h"
#include "UObject/UnrealType.h"
#include "IStructDeserializerBackend.h"
#include "UObject/PropertyPortFlags.h"
/* Internal helpers
*****************************************************************************/
namespace StructDeserializer
{
/**
* Structure for the read state stack.
*/
struct FReadState
{
/** Holds the property's current array index. */
int32 ArrayIndex;
/** Holds a pointer to the property's data. */
void* Data;
/** Holds the property's meta data. */
UProperty* Property;
/** Holds a pointer to the UStruct describing the data. */
UStruct* TypeInfo;
};
/**
* Finds the class for the given stack state.
*
* @param State The stack state to find the class for.
* @return The class, if found.
*/
UStruct* FindClass( const FReadState& State )
{
UStruct* Class = nullptr;
if (State.Property != nullptr)
{
UProperty* ParentProperty = State.Property;
UArrayProperty* ArrayProperty = Cast<UArrayProperty>(ParentProperty);
if (ArrayProperty != nullptr)
{
ParentProperty = ArrayProperty->Inner;
}
UStructProperty* StructProperty = Cast<UStructProperty>(ParentProperty);
UObjectPropertyBase* ObjectProperty = Cast<UObjectPropertyBase>(ParentProperty);
if (StructProperty != nullptr)
{
Class = StructProperty->Struct;
}
else if (ObjectProperty != nullptr)
{
Class = ObjectProperty->PropertyClass;
}
}
else
{
UObject* RootObject = static_cast<UObject*>(State.Data);
Class = RootObject->GetClass();
}
return Class;
}
}
/* FStructDeserializer static interface
*****************************************************************************/
bool FStructDeserializer::Deserialize( void* OutStruct, UStruct& TypeInfo, IStructDeserializerBackend& Backend, const FStructDeserializerPolicies& Policies )
{
using namespace StructDeserializer;
check(OutStruct != nullptr);
// initialize deserialization
FReadState CurrentState;
{
CurrentState.ArrayIndex = 0;
CurrentState.Data = OutStruct;
CurrentState.Property = nullptr;
CurrentState.TypeInfo = &TypeInfo;
}
TArray<FReadState> StateStack;
EStructDeserializerBackendTokens Token;
// process state stack
while (Backend.GetNextToken(Token))
{
FString PropertyName = Backend.GetCurrentPropertyName();
switch (Token)
{
case EStructDeserializerBackendTokens::ArrayEnd:
{
if (StateStack.Num() == 0)
{
UE_LOG(LogSerialization, Verbose, TEXT("Malformed input: Found ArrayEnd without matching ArrayStart"));
return false;
}
CurrentState = StateStack.Pop(/*bAllowShrinking*/ false);
}
break;
case EStructDeserializerBackendTokens::ArrayStart:
{
FReadState NewState;
NewState.Property = FindField<UProperty>(CurrentState.TypeInfo, *PropertyName);
if (NewState.Property != nullptr)
{
// handle array property
if (Policies.PropertyFilter && Policies.PropertyFilter(NewState.Property, CurrentState.Property))
{
continue;
}
NewState.ArrayIndex = 0;
NewState.Data = CurrentState.Data;
NewState.TypeInfo = FindClass(NewState);
StateStack.Push(CurrentState);
CurrentState = NewState;
}
else
{
// error: array property not found
if (Policies.MissingFields != EStructDeserializerErrorPolicies::Ignore)
{
UE_LOG(LogSerialization, Verbose, TEXT("The array property '%s' does not exist"), *PropertyName);
}
if (Policies.MissingFields == EStructDeserializerErrorPolicies::Error)
{
return false;
}
Backend.SkipArray();
}
}
break;
case EStructDeserializerBackendTokens::Error:
{
return false;
}
case EStructDeserializerBackendTokens::Property:
{
if (PropertyName.IsEmpty())
{
// handle array element
UArrayProperty* ArrayProperty = Cast<UArrayProperty>(CurrentState.Property);
UProperty* Property = nullptr;
if (ArrayProperty != nullptr)
{
// dynamic array element
Property = ArrayProperty->Inner;
}
else
{
// static array element
Property = CurrentState.Property;
}
if (Property == nullptr)
{
// error: no meta data for array element
if (Policies.MissingFields != EStructDeserializerErrorPolicies::Ignore)
{
UE_LOG(LogSerialization, Verbose, TEXT("Failed to serialize array element %i"), CurrentState.ArrayIndex);
}
return false;
}
else if (!Backend.ReadProperty(Property, CurrentState.Property, CurrentState.Data, CurrentState.ArrayIndex))
{
UE_LOG(LogSerialization, Verbose, TEXT("The array element '%s[%i]' could not be read (%s)"), *PropertyName, CurrentState.ArrayIndex, *Backend.GetDebugString());
}
++CurrentState.ArrayIndex;
}
else if ((CurrentState.Property != nullptr) && (CurrentState.Property->GetClass() == UMapProperty::StaticClass()))
{
// handle map element
UMapProperty* MapProperty = Cast<UMapProperty>(CurrentState.Property);
FScriptMapHelper MapHelper(MapProperty, CurrentState.Data);
UProperty* Property = MapProperty->ValueProp;
int32 PairIndex = MapHelper.AddDefaultValue_Invalid_NeedsRehash();
uint8* PairPtr = MapHelper.GetPairPtr(PairIndex);
MapProperty->KeyProp->ImportText(*PropertyName, PairPtr, PPF_None, nullptr);
if (!Backend.ReadProperty(Property, CurrentState.Property, PairPtr, CurrentState.ArrayIndex))
{
UE_LOG(LogSerialization, Verbose, TEXT("An item in map '%s' could not be read (%s)"), *PropertyName, *Backend.GetDebugString());
}
}
else if ((CurrentState.Property != nullptr) && (CurrentState.Property->GetClass() == USetProperty::StaticClass()))
{
// handle set element
USetProperty* SetProperty = Cast<USetProperty>(CurrentState.Property);
FScriptSetHelper SetHelper(SetProperty, SetProperty->ContainerPtrToValuePtr<void>(CurrentState.Data));
UProperty* Property = SetProperty->ElementProp;
const int32 ElementIndex = SetHelper.AddDefaultValue_Invalid_NeedsRehash();
uint8* ElementPtr = SetHelper.GetElementPtr(ElementIndex);
if (!Backend.ReadProperty(Property, CurrentState.Property, ElementPtr, CurrentState.ArrayIndex))
{
UE_LOG(LogSerialization, Verbose, TEXT("An item in Set '%s' could not be read (%s)"), *PropertyName, *Backend.GetDebugString());
}
}
else
{
// handle scalar property
UProperty* Property = FindField<UProperty>(CurrentState.TypeInfo, *PropertyName);
if (Property != nullptr)
{
if (Policies.PropertyFilter && Policies.PropertyFilter(Property, CurrentState.Property))
{
continue;
}
if (!Backend.ReadProperty(Property, CurrentState.Property, CurrentState.Data, CurrentState.ArrayIndex))
{
UE_LOG(LogSerialization, Verbose, TEXT("The property '%s' could not be read (%s)"), *PropertyName, *Backend.GetDebugString());
}
}
else
{
// error: scalar property not found
if (Policies.MissingFields != EStructDeserializerErrorPolicies::Ignore)
{
UE_LOG(LogSerialization, Verbose, TEXT("The property '%s' does not exist"), *PropertyName);
}
if (Policies.MissingFields == EStructDeserializerErrorPolicies::Error)
{
return false;
}
}
}
}
break;
case EStructDeserializerBackendTokens::StructureEnd:
{
// rehash if value was a map
UMapProperty* MapProperty = Cast<UMapProperty>(CurrentState.Property);
if (MapProperty != nullptr)
{
FScriptMapHelper MapHelper(MapProperty, CurrentState.Data);
MapHelper.Rehash();
}
// rehash if value was a set
USetProperty* SetProperty = Cast<USetProperty>(CurrentState.Property);
if (SetProperty != nullptr)
{
FScriptSetHelper SetHelper(SetProperty, CurrentState.Data);
SetHelper.Rehash();
}
if (StateStack.Num() == 0)
{
return true;
}
CurrentState = StateStack.Pop(/*bAllowShrinking*/ false);
}
break;
case EStructDeserializerBackendTokens::StructureStart:
{
FReadState NewState;
if (PropertyName.IsEmpty())
{
// skip root structure
if (CurrentState.Property == nullptr)
{
continue;
}
// handle struct element inside array
UArrayProperty* ArrayProperty = Cast<UArrayProperty>(CurrentState.Property);
if (ArrayProperty == nullptr)
{
UE_LOG(LogSerialization, Verbose, TEXT("Found unnamed value outside of array"));
return false;
}
FScriptArrayHelper ArrayHelper(ArrayProperty, ArrayProperty->ContainerPtrToValuePtr<void>(CurrentState.Data));
const int32 ArrayIndex = ArrayHelper.AddValue();
NewState.Property = ArrayProperty->Inner;
NewState.Data = ArrayHelper.GetRawPtr(ArrayIndex);
}
else if ((CurrentState.Property != nullptr) && (CurrentState.Property->GetClass() == UMapProperty::StaticClass()))
{
// handle map or struct element inside map
UMapProperty* MapProperty = Cast<UMapProperty>(CurrentState.Property);
FScriptMapHelper MapHelper(MapProperty, CurrentState.Data);
int32 PairIndex = MapHelper.AddDefaultValue_Invalid_NeedsRehash();
uint8* PairPtr = MapHelper.GetPairPtr(PairIndex);
NewState.Data = PairPtr + MapHelper.MapLayout.ValueOffset;
NewState.Property = MapProperty->ValueProp;
MapProperty->KeyProp->ImportText(*PropertyName, PairPtr, PPF_None, nullptr);
}
else if ((CurrentState.Property != nullptr) && (CurrentState.Property->GetClass() == USetProperty::StaticClass()))
{
// handle map or struct element inside map
USetProperty* SetProperty = Cast<USetProperty>(CurrentState.Property);
FScriptSetHelper SetHelper(SetProperty, CurrentState.Data);
const int32 ElementIndex = SetHelper.AddDefaultValue_Invalid_NeedsRehash();
uint8* ElementPtr = SetHelper.GetElementPtr(ElementIndex);
NewState.Data = ElementPtr;
NewState.Property = SetProperty->ElementProp;
}
else
{
NewState.Property = FindField<UProperty>(CurrentState.TypeInfo, *PropertyName);
if (NewState.Property == nullptr)
{
// error: map, set, or struct property not found
if (Policies.MissingFields != EStructDeserializerErrorPolicies::Ignore)
{
UE_LOG(LogSerialization, Verbose, TEXT("Map, Set, or struct property '%s' not found"), *PropertyName);
}
if (Policies.MissingFields == EStructDeserializerErrorPolicies::Error)
{
return false;
}
}
else if (NewState.Property->GetClass() == UMapProperty::StaticClass())
{
// handle map property
UMapProperty* MapProperty = Cast<UMapProperty>(NewState.Property);
NewState.Data = MapProperty->ContainerPtrToValuePtr<void>(CurrentState.Data, CurrentState.ArrayIndex);
FScriptMapHelper MapHelper(MapProperty, NewState.Data);
MapHelper.EmptyValues();
}
else if (NewState.Property->GetClass() == USetProperty::StaticClass())
{
// handle set property
USetProperty* SetProperty = Cast<USetProperty>(NewState.Property);
NewState.Data = SetProperty->ContainerPtrToValuePtr<void>(CurrentState.Data, CurrentState.ArrayIndex);
FScriptSetHelper SetHelper(SetProperty, NewState.Data);
SetHelper.EmptyElements();
}
else
{
// handle struct property
NewState.Data = NewState.Property->ContainerPtrToValuePtr<void>(CurrentState.Data);
}
}
if (NewState.Property != nullptr)
{
// skip struct property if property filter is set and rejects it
if (Policies.PropertyFilter && !Policies.PropertyFilter(NewState.Property, CurrentState.Property))
{
Backend.SkipStructure();
continue;
}
NewState.ArrayIndex = 0;
NewState.TypeInfo = FindClass(NewState);
StateStack.Push(CurrentState);
CurrentState = NewState;
}
else
{
// error: structured property not found
Backend.SkipStructure();
if (Policies.MissingFields != EStructDeserializerErrorPolicies::Ignore)
{
UE_LOG(LogSerialization, Verbose, TEXT("Structured property '%s' not found"), *PropertyName);
}
if (Policies.MissingFields == EStructDeserializerErrorPolicies::Error)
{
return false;
}
}
}
default:
continue;
}
}
// root structure not completed
return false;
}